Individuals with neurological injuries and auto-immune diseases such as spinal cord injury, stroke, Lupus, Muscular Dystrophy, Myasthenia and Multiple Sclerosis often have difficulty walking. Approximately one third of people that experience a stroke will not be able to walk or will require assistance to walk 3 months after their stroke (See Jorgensen et al. 1995.) and between 30% and 50% of individuals with Multiple Sclerosis have difficulty walking. See Ghezzi et al., 2002; Pittock et al., 2004; and Myhr et al., 2001. Locomotor training utilizing a body weight support system and treadmill, as shown below in FIG. 1, has been advocated as an effective intervention strategy to improve walking ability for individuals with stroke, spinal cord injury and MS. See Sullivan et al. 2002; Dobkin, 1999; Fulk, 2004; Nilsson, 2001 Behrman et al., 2000; Dobkin et al., 2003; and Fulk, 2005 cited below. Locomotor training principles were developed from basic science research with spinalized cats. See Lovely et al., 1986; Edgerton et al. 1991; Barbeau et al., 1987; and Barbeau 2003.
Based on this translational research, Behrman and Harkema, (See Behrman et al., 2000.) developed an expanded list of guiding principles for locomotive training with humans. These principles include: 1) training at stepping speeds that approximate normal walking speeds, 2) maintain maximum sustainable load on the lower extremities in stance, 3) maintain an erect head and trunk, 4) approximate normal lower extremities kinematics when stepping, 5) synchronize hip extension with loading of the opposite lower extremities, 6) minimize weight bearing on the arms and facilitate reciprocal arm swing, and 7) minimize sensory stimulation that is in conflict with normal sensory information consistent with walking.
Following these principles will optimize sensory input related to walking, thereby optimizing the development of neural patterns for locomotion. These principles emphasize recovery of locomotion using the intrinsic mechanisms of the nervous system rather than compensation strategies.
An important component of locomotive training is to apply these principles while training over ground and in the community as well as with body weight support on a tread mill. The end goal of the training is for the clients to be able to walk independently in their home and community. Currently, physical therapists utilize various assistive devices such as walkers, canes, and crutches when locomotor training over ground and in the community. However, these devices may not allow for the effective application of Behrman and Harkema's guiding principles, as stated above. For example, when an individual utilizes a rolling-style walker, also known as a rollator, to ambulate their trunk is flexed throughout the gait cycle, as shown below in FIG. 2.
The rolling type of ambulatory assistive device does not allow for natural hip extension at the end of stance or other normal kinematics in the lower extremity and upper extremity joints. Furthermore, rollators do not permit the type of reciprocal arm swing associated with natural gait. Non-wheeled walkers have a further disadvantage of a requiring a cyclical lifting motion that further deviates from normal gait. Other assistive ambulatory devices, such as crutches or canes, may also alter gait kinematics when walking and allow for increased weight bearing on lower extremity joints and the arms, which may provide inappropriate sensory feedback to the spinal cord that does not resemble normal gait.